The present invention relates to the reclaiming of synthetic material for metal and/or synthetic waste. Specifically the present invention relates to such a method as well as to equipment for the recovery of synthetic material from waste so that the recovered material is substantially metalfree particularly from a blend of synthetic material and metal such as the waste resulting in cable manufacture. The invention moreover refers to the preparation of the reclaimed synthetic and/or metal material of easy re-use.
Reclaiming this or that product is generally known and many proposals have been made along that line with particular emphasis on the problem resulting from the fact that the waste or scrap material is a blend, so to speak, of many different kinds of material and different components; with emphasis in the past on reclaiming of any metal. German printed patent application 21 01 739 has proposed to expose the scrap or waste to low temperatures so that any synthetic material cover or coating is made very brittle following which it is fairly easy to remove the synthetic material from the metal, the brittle plastic just crumbles even if originally it firmly adhered to a conductor on which it was deposited. Of course it can readily be seen that the cooling is an energy extensive process and is in fact generally expensive. Still metal is sufficiently valuable to undergo the expenses in many instances while on the other hand the synthetic material is not reclaimed.
German printed patent application 23 47 108 is directed to a basically similar method but with different execution. The metal synthetic blend or compound parts are cooled also here, but subsequently subjected to ultrasonic vibration or magnetic vibration so as to separate metal from synthetic. The synthetic is not reclaimed here.
German printed patent 30 39 870 refers to the reclaiming of components from a compound structure that includes rubber and metal. Rather than cooling the raw charges this patent proposes annealing particularly of the metal part whereby the rubber decomposes. Obviously the rubber following such excessive heat treatment cannot be reused. The same is true for a similar method as per German printed patent application 34 22 942 wherein such a compound body is exposed to hot vapor of a solvent which provides the solving of the synthetic and/or rubber from metal substrate.
Another method for separating metal wires from the insulation is disclosed in German printed patent application 19 24 640 and provides for a plural step mechanical cutting of the wire and the cut blend of wire pieces and other materials are then subjected to a multistage electrostatic processing. Heavier components are separated through a weak air current from lighter ones. The resulting metal granulate is collected and reused.
It can readily be seen that in all these methods and in this known practice emphasis is on the reclaiming of metal, on freeing the metal from other parts such as synthetic and rubber, and no interest had been voiced to reclaim also the synthetic and/or rubber. Often and for one reason or another this seems to be impossible.